Confirmatory interleukin-1 receptor antagonist trial in severe sepsis: a phase III, randomized, double-blind, placebo-controlled, multicenter trial. The Interleukin-1 Receptor Antagonist Sepsis Investigator Group

OBJECTIVE

To determine the therapeutic efficacy and safety of recombinant human interleukin-1 receptor antagonist (rhIL-1ra) in the treatment of patients with severe sepsis.

DESIGN

Prospective, randomized, double-blind, placebo-controlled, multicenter trial with a planned, midstudy, interim analysis.

SETTING

Ninety-one academic medical center intensive care units in North America and Europe.

PATIENTS

Patients with severe sepsis or septic shock (n = 696) received standard supportive care and antimicrobial therapy for sepsis, in addition to rhIL-1ra or placebo.

INTERVENTIONS

Patients were randomized to receive either rhIL-1ra (100 mg) or placebo (vehicle) by intravenous bolus, followed by a 72-hr continuous intravenous infusion of either rhIL-1ra (2.0 mg/kg/hr) or placebo.

MEASUREMENTS AND MAIN RESULTS

The study was terminated after an interim analysis found that it was unlikely that the primary efficacy end points would be met. The 28-day, all-cause mortality rate was 33.1% (116/350) in the rhIL-1ra treatment group, while the mortality rate in the placebo group was 36.4% (126/346), yielding a 9% reduction in mortality rate (p = .36). The patients were well matched at the time of study entry; 52.9% of placebo-treated patients were in shock while 50.9% of rhIL-1ra-treated patients were in shock at the time of study entry (p = .30). The mortality rate did not significantly differ between treatment groups when analyzed on the basis of site of infection, infecting microorganism, presence of bacteremia, shock, organ dysfunction, or predicted risk of mortality at the time of study entry. No excess number of adverse reactions or microbial superinfections were attributable to rhIL-1ra treatment in this study.

CONCLUSIONS

A 72-hr, continuous intravenous infusion of rhIL-1ra failed to demonstrate a statistically significant reduction in mortality when compared with standard therapy in this multicenter clinical trial. If rhIL-1ra treatment has any therapeutic activity in severe sepsis, the incremental benefits are small and will be difficult to demonstrate in a patient population as defined by this clinical trial.

The role of cytokines in the pathogenesis of acute pancreatitis

BACKGROUND

The systemic manifestations of acute pancreatitis are responsible for the majority of pancreatitis-associated morbidity and mortality and are now believed to be due to the actions of specific inflammatory cytokines. This report summarizes what is known about the role of cytokines in the pathogenesis of acute pancreatitis.

METHODS

Comprehensive literature review of experimental pancreatitis as well as all reports of cytokine involvement during clinical pancreatitis.

RESULTS

Several cytokines and other noncytokine inflammatory mediators are produced rapidly during pancreatitis. These mediators arise in many tissues in a predictable fashion independent of the animal model used or the underlying etiology in human disease. Preventing the activities of these mediators has a profound beneficial effect in experimental animals.

CONCLUSIONS

A few recently described inflammatory mediators are believed to be primarily responsible for the systemic manifestations of acute pancreatitis and its associated distant organ dysfunction. The predictable nature in which they are produced may allow for novel approaches to treating this disease. Am J Surg.

PDGF-regulated rab4-dependent recycling of alphavbeta3 integrin from early endosomes is necessary for cell adhesion and spreading

BACKGROUND

It has been postulated that the regulation of integrin vesicular traffic facilitates cell migration by internalizing integrins at the rear of the cell and transporting them forward within vesicles for exocytosis at the leading edge to form new contacts with the extracellular matrix. The rab family of GTPases control key targeting events in the endo/exocytic pathway; therefore, these GTPases may be involved in the regulation of cell-matrix contact assembly.

RESULTS

The endo/exocytic cycle of alphavbeta3 and alpha5beta1 integrins was studied using mouse 3T3 fibroblast cell lines. In serum-starved cells, internalized integrins were transported through rab4-positive, early endosomes and arrived at the rab11-positive, perinuclear recycling compartment approximately 30 min after endocytosis. From the recycling compartment, integrins were recycled to the plasma membrane in a rab11-dependent fashion. Following treatment with PDGF, alphavbeta3 integrin, but not alpha5beta1, was rapidly recycled directly back to the plasma membrane from the early endosomes via a rab4-dependent mechanism without the involvement of rab11. This rapid recycling pathway directed alphavbeta3 to numerous small puncta distributed evenly across the dorsal surface of the cell, and the integrin only became localized into focal complexes at later times following PDGF addition. Interestingly, inhibition of PDGF-stimulated alphavbeta3 recycling using dominant-negative rab4 mutants compromised cell adhesion and spreading on vitronectin (a ligand for alphavbeta3), but adhesion to fibronectin (a ligand for alpha5beta1 and alphavbeta3) was unchanged.

CONCLUSIONS

We propose that growth factor-regulated, rab4-dependent recycling of alphavbeta3 integrin from early endosomes to the plasma membrane is a critical upstream event in the assembly of cell-matrix contacts.

Minimally invasive parathyroidectomy facilitated by intraoperative nuclear mapping

BACKGROUND

The inability to predict the location and number of diseased parathyroid glands has precluded the wide acceptance of unilateral neck exploration for primary hyperparathyroidism. We used intraoperative nuclear mapping in patients identified by sestamibi scanning to have a single adenoma in hopes of minimizing operative intervention while maintaining the efficacy of a full exploration.

METHODS

Fifteen consecutive patients with primary hyperparathyroidism underwent technetium 99m-labeled sestamibi scanning 3.0 +/- 0.1 hours before operation. Placement of the initial 2.0 cm incision and all dissection were guided by quantitative gamma counting in four neck quadrants with an 11 mm Neoprobe. Ex vivo radioactivity was determined for parathyroid glands, fat, and lymph nodes. Potential radiation hazards were assessed.

RESULTS

Intraoperative nuclear mapping discriminated between 14 solitary adenomas and one patient with four-gland hyperplasia that was not predicted on preoperative sestamibi scanning. Removal of the adenoma resulted in a decline in radioactivity in that quadrant (p < 0.001) and the entire neck (p < 0.05), with equalization of all neck quadrants. Ex vivo counts always identified parathyroid tissue (p < 0.0001 versus fat and lymph node). Adenomas were located in 19 +/- 1.7 minutes through a 2.3 +/- 0.1 cm incision. No significant radiation hazard existed, and no special handling of the specimen was required (0.06 +/- 0.01 mR/hr).

CONCLUSIONS

Intraoperative nuclear mapping complements sestamibi scanning to help distinguish single-gland from multigland disease. This technique allows for a minimally invasive operation under local anesthesia in a true outpatient setting.

An improved plasmid DNA expression vector for direct injection into skeletal muscle

In previous work, the direct injection of 50 micrograms of a plasmid DNA vector encoding firefly luciferase (VR1205) into murine quadriceps muscle produced an average of 6.5 ng of luciferase per muscle at 7 days postinjection. In this report, various elements of the VR1205 vector were modified to increase gene expression levels or to eliminate undesired viral sequences. Expression of the modified vectors was then compared to VR1205 using the intramuscular injection assay. In general, modifications to promoter, enhancer, and intronic sequences either decreased luciferase expression levels or had no effect. However, modifications to the polyadenylation and transcriptional termination sequences, plasmid backbone elements, and the luciferase gene itself each increased luciferase expression levels. The best-expressing vector, designated VR1255, contained a combination of these incrementally beneficial changes. A single intramuscular injection of 50 micrograms of VR1255 produced 300 ng of luciferase at 7 days postinjection, an expression level 46-fold higher than the VR1205 vector (or 22-fold higher, excluding modifications to the luciferase gene) and 154-fold higher than a commercially available luciferase expression vector. Thus, VR1255 represents an improved plasmid DNA vector that may be useful for gene therapy applications.

Propofol: clinical strategies for preventing the pain of injection

Eight modes of administration of propofol were assessed in order to minimise the pain of injection. An intravenous bolus injection in the antecubital fossa was the only approach that caused no pain. When administered intravenously in the dorsum of the hand the pain score and the number of patients who experienced pain was reduced significantly by mixing the agent with lignocaine when compared with a bolus injection. Slowing the speed of injection caused the greatest discomfort. An indirect biochemical mechanism for the pain is proposed.

A novel cationic lipid greatly enhances plasmid DNA delivery and expression in mouse lung

Effective gene therapy for lung tissue requires the use of efficient vehicles to deliver the gene of interest into lung cells. When plasmid DNA encoding chloramphenicol acetyltransferase (CAT) was administered intranasally to BALB/c mice without carrier lipids, CAT activity was detected in mouse lung extracts. Plasmid DNA delivered with optimally formulated commercially available transfection reagents expressed up to 10-fold more CAT activity in lung than observed with naked DNA alone. Liposome formulations consisting of (+/-)-N-(3-aminopropyl)-N,N-dimethyl-2,3-bis (dodecyloxy)-1-propanaminium bromide (GAP-DLRIE) plus the neutral colipid dioleoylphosphatidylethanolamine (DOPE) enhanced CAT expression by more than 100-fold relative to plasmid DNA alone. A single administration of GAP-DLRIE liposome-CAT DNA complexes to mouse lung elicited peak expression at days 1-4 posttransfection, followed by a gradual return to baseline by day 21 postadministration. Readministration of GAP-DLRIE liposome CAT complexes at day 21 led to another transient peak of reporter gene expression. Histological examination of lungs treated with GAP-DLRIE complexed beta-galactosidase DNA revealed that alveolar epithelial cells were the primary locus of expression and that up to 1% of all alveoli contained epithelial cells expressing the transgene.

Relation between QT interval and heart rate. New design of physiologically adaptive cardiac pacemaker

The relation between QT interval and heart rate has been studied in a group of patients undergoing physiological exercise, in a group undergoing atrial pacing without exercise, and in a group with complete heart block undergoing exercise at a fixed ventricular rate controlled by cardiac pacing. The expected shortening in QT interval during physiological exercise is only in part the result of the intrinsic effect of increased rate, since patients undergoing atrial pacing to comparable rates show only a small decrease in measured QT interval and patients exercising at fixed rates in heart block exhibit a decreasing QT interval related to the independent atrial rate. QT interval changes appear mainly to be governed by factors extrinsic to heart rate. The physiological control of QT interval has been used to construct a cardiac pacemaker which senses the interval between the delivered stimulus and the evoked T wave, and uses the stimulus-evoked T wave interval to set the subsequent pacemaker escape interval. Thus physiological control of cardiac pacing rate, independent of atrial activity, using conventional unipolar lead systems is possible.

Redefinition of cutaneous lymphatic drainage with the use of lymphoscintigraphy for malignant melanoma

Lymphoscintigraphy was performed on 82 patients with melanoma registered at the University Melanoma Clinic. From these data, precise lymphatic drainage basins could be drawn for the head, neck, shoulder, and trunk. These drawings differed significantly from the classic anatomic studies, providing a functional look at the cutaneous lymphatic drainage. This new method correlates much better with clinical experiences and demonstrates much larger areas of ambiguous drainage than previously reported. Data from the lymphoscintigrams also emphasize the individuality of cutaneous lymphatic flow. The implications of these data in planning elective node dissections for intermediate thickness melanomas are obvious, since it is estimated that up to 59% of the dissections for trunk and head and neck primary melanomas may be misdirected if based on classic anatomic studies. The data indicate that all patients with head, neck, and shoulder lesions should undergo lymphoscintigraphy to define possible drainage basins at risk for metastatic disease. Similarly, truncal lesions require scintigrams except when they are within four well-defined areas with an extremely low probability of ambiguous drainage. Lesions in these areas show very reliable and predictable drainage to a single nodal group.

Cost-effectiveness of preoperative sestamibi scan for primary hyperparathyroidism is dependent solely upon the surgeon's choice of operative procedure

BACKGROUND

In 1991, a National Institutes of Health Consensus Panel stated that preoperative localization for primary hyperparathyroidism is not cost effective. Since then, the sestamibi scan has been applied to parathyroid disease with excellent results, even allowing unilateral exploration under local anesthesia.

STUDY DESIGN

A metaanalysis of the English literature over the past 10 years was performed to determine the collective sensitivity and specificity of sestamibi scanning to establish its utility in directing a unilateral procedure. The cost effectiveness of scanning all patients with sporadic primary hyperparathyroidism was examined by determining the costs of seven operative technique-dependent variables that could be reduced with a limited procedure.

RESULTS

The average sensitivity and specificity of sestamibi were 90.7% and 98.8%, respectively, indicating its ability to guide an accurate unilateral exploration. The analysis of 6,331 patients showed that 87% had solitary adenomas. An average cost savings of $650 was demonstrated for a unilateral operation, which could be realized in as many as 90% (sestamibi sensitivity) of those with solitary adenomas.

CONCLUSIONS

A preoperative sestamibi scan is specific enough in identifying solitary adenomas to allow unilateral exploration with a < 1% failure rate. The sensitivity of this scan suggests that 78% of all patients with sporadic primary hyperparathyroidism (90% of the 87% with solitary adenomas) are candidates for unilateral exploration. This rate is significantly higher than the 51% rate at which scanning all patients becomes cost effective.

Safety, tolerability and humoral immune responses after intramuscular administration of a malaria DNA vaccine to healthy adult volunteers

DNA-based vaccines are considered to be potentially revolutionary due to their ease of production, low cost, long shelf life, lack of requirement for a cold chain and ability to induce good T-cell responses. Twenty healthy adult volunteers were enrolled in a Phase I safety and tolerability clinical study of a DNA vaccine encoding a malaria antigen. Volunteers received 3 intramuscular injections of one of four different dosages (20, 100, 500 and 2500 microg) of the Plasmodium falciparum circumsporozoite protein (PfCSP) plasmid DNA at monthly intervals and were followed for up to twelve months. Local reactogenicity and systemic symptoms were few and mild. There were no severe or serious adverse events, clinically significant biochemical or hematologic changes, or detectable anti-dsDNA antibodies. Despite induction of excellent CTL responses, intramuscular DNA vaccination via needle injection failed to induce detectable antigen-specific antibodies in any of the volunteers.

Induction of CD4(+) T cell-dependent CD8(+) type 1 responses in humans by a malaria DNA vaccine

We assessed immunogenicity of a malaria DNA vaccine administered by needle i.m. or needleless jet injection [i.m. or i.m./intradermally (i.d.)] in 14 volunteers. Antigen-specific IFN-gamma responses were detected by enzyme-linked immunospot (ELISPOT) assays in all subjects to multiple 9- to 23-aa peptides containing class I and/or class II restricted epitopes, and were dependent on both CD8(+) and CD4(+) T cells. Overall, frequency of response was significantly greater after i.m. jet injection. CD8(+)-dependent cytotoxic T lymphocytes (CTL) were detected in 8/14 volunteers. Demonstration in humans of elicitation of the class I restricted IFN-gamma responses we believe necessary for protection against the liver stage of malaria parasites brings us closer to an effective malaria vaccine.

Interleukin-1 receptor antagonist decreases severity of experimental acute pancreatitis

BACKGROUND

Fulminant acute pancreatitis is a disease of complex origin that results in activation of several of the proinflammatory cytokines. Because interleukin-1 (IL-1) is an integral early component of the acute inflammatory process, the use of an IL-1 receptor antagonist (IL-1ra) was investigated in experimental acute pancreatitis to determine the therapeutic potential of proximal cytokine blockade and to further establish the role of inflammatory cytokines in the pathogenesis of acute pancreatitis.

METHODS

IL-1ra was administered in escalating doses either before or after acute edematous, necrotizing pancreatitis was induced in adult male mice by injection of cerulein. The severity of pancreatitis was quantified by serum amylase, lipase, interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) levels, pancreatic wet weight, and blinded histologic grading.

RESULTS

Administration of medium (10 mg/kg) and high (100 mg/kg) doses of IL-1ra either before or after the induction of pancreatitis significantly decreased the expected rise in pancreatic wet weight, lipase, IL-6, and TNF-alpha (all, p < 0.01). Serum amylase was significantly reduced when IL-1ra was administered in either dosage before (p < 0.05), but not after, induction of pancreatitis. Pancreatic edema, necrosis, and inflammatory cell infiltrate were significantly diminished (p < 0.05) by histologic grading in all animals receiving medium or high doses of IL-1ra. Low doses of IL-1ra (1.0 mg/kg) had modest effects if given before, but no effect if given after, induction of pancreatitis.

CONCLUSIONS

The proinflammatory cytokines IL-6 and TNF-alpha are elevated during experimental acute pancreatitis and correlate well with the severity of local pancreatic destruction. Blockade of the cytokine cascade at the level of the IL-1 receptor before or soon after induction of pancreatitis significantly attenuates the rise in these cytokines and is associated with decreased severity of pancreatitis and reduced intrinsic pancreatic damage.

The 20% rule: a simple, instantaneous radioactivity measurement defines cure and allows elimination of frozen sections and hormone assays during parathyroidectomy

BACKGROUND

Although primary hyperparathyroidism is a physiologic disease, surgeons rely on anatomical characteristics (gross and histologic) to determine appropriate operative decisions. After the development of radioguided parathyroidectomy, we hypothesized that the amount of radioactivity contained within resected tissue would be the only information needed to establish the nature of the tissue and to determine a cure for the disease.

METHODS

A total of 1290 tissue specimens were obtained from 345 patients who had sporadic primary hyperparathyroidism. Ex-vivo radioactivity, in counts per second, was measured in parathyroid and other tissues within 3.5 hours of sestamibi injection. Background radioactivity was measured after tissue excision, and ratios were calculated.

RESULTS

Lymph nodes, normal parathyroids, and fat never contained more than 2.2% of background radioactivity, whereas thyroid and hyperplastic parathyroids contained 5.5% and 7.5%, respectively, and never more than 16%. In contrast, adenomas contained 59% +/- 9% of background radioactivity (P < .000001 vs all other tissues), with a range of 18% to 136%.

CONCLUSIONS

Radioactive ratios are an instantaneous measure of metabolic activity, thereby determining parathyroid function. Any excised tissue containing more than 20% of background radioactivity in a patient with a positive sestamibi scan result is a solitary parathyroid adenoma. This alleviates the need to identify other glands, obtain frozen sections, or measure serum parathyroid hormone levels intraoperatively.

Cardiovascular risk assessment using pulse pressure in the first national health and nutrition examination survey (NHANES I)

Increased stiffness of the conduit arteries has been associated with increased risk of death and cardiovascular death in a number of populations. None of these populations, however, are fully representative of the US population. The cohort examined in the First National Health and Nutrition Examination Survey (NHANES I) that was free of overt cardiovascular disease was selected to be representative of the US population. We assessed and quantified the increased risk of death associated with elevated pulse pressure in this population. A cohort of 5771 subjects from NHANES I was used to determine the value of adding pulse pressure to standard cardiovascular disease risk factors for assessment of the risk of death during a mean follow-up period of 16.5 years. Analyses were performed by use of the SUDAAN statistical package for performing Cox proportional regression, logistic regression, and other standard methods in complex, weighted samples. Pulse pressure increased with increasing age, body mass index, cholesterol level, and mean arterial pressure. With increasing pulse pressure, the percentage of cigarette smokers decreased and the percentage of diabetics increased. Despite these associations with known risk factors, pulse pressure was independently predictive of an increased risk of death from cardiovascular disease, coronary heart disease, and all-cause mortality. It provides independent prognostic information beyond that provided by known risk factors that were evaluated in this study, including the Sixth Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure hypertension classification. A 10 mm Hg increase in pulse pressure in persons 25 to 45 of age was associated with a 26% increase in risk of cardiovascular death (95% confidence interval [CI], 5 to 50) and with an 10% increase (95% CI, 2 to 19) in persons 46 to 77 years of age. In a cohort designed to be representative of the US population, elevated pulse pressure has been shown to provide independent prognostic information. This variable may be a marker for the extent of vascular disease and may contribute to the occurrence of clinical events.

Gene targeting demonstrates additive detrimental effects of interleukin 1 and tumor necrosis factor during pancreatitis

BACKGROUND & AIMS

During severe pancreatitis, interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha are produced in large quantities. The aim of this study was to determine whether either one plays a more dominant role and if their detrimental effects are additive.

METHODS

Necrotizing pancreatitis was induced in transgenic (-/-) knockout mice deficient in either IL-1 type 1 receptors, TNF type 1 receptors, or both IL-1 and TNF type 1 receptors. Wild-type mice served as controls. Mortality was assessed for 10 days. Additional animals were killed on days 0, 1, 2, 3, and 4 for determination of pancreatitis severity.

RESULTS

All three knockout groups showed decreased amylase and lipase, histological score, serum IL-6, and mortality compared with wild-type groups. Animals devoid of receptors for both cytokines showed improved survival and decreased IL-6 levels compared with those devoid of either IL-1 or TNF receptors individually, yet they failed to show a further decrease in pancreatitis severity.

CONCLUSIONS

Preventing the activity of IL-1beta or TNF-alpha has a nearly identical beneficial effect on the severity and mortality of acute pancreatitis. Preventing the activity of both cytokines concurrently has no additional effect on pancreatitis severity but further attenuates the systemic stress response and is associated with an additional but modest decrease in mortality.

Role of IL-1 in renal ischemic reperfusion injury

Interleukin-1 (IL-1) is a central component of many acute inflammatory processes. Blocking IL-1 receptor (IL-1R) with IL-1R antagonist (IL-1Ra) has attenuated ischemic reperfusion injury in brain, heart, and liver models. However, the role of IL-1 in renal ischemic reperfusion injury (IRI) is not known. Therefore, the role of IL-1 in renal IRI was evaluated using the complementary approaches of IL-1R blockade in wild-type mice in addition to the study of renal IRI in IL-1R knockout (KO) mice. Ischemia was induced by bilateral renal pedicle clamping for 30 min. IL-1Ra was administered at 10 mg/kg every 4 h, high doses that have been protective in previous organ injury models in mice. IL-1R KO animals, previously characterized as insensitive to IL-1, had the absence of IL-1R1 confirmed by DNA blots. IL-1Ra, IL-1R KO, and control groups had similar elevations of blood urea nitrogen (114 +/- 13, 133 +/- 11, and 120 +/- 11 mg/dl) and serum creatinine (1.7 +/- 0.3, 2.1 +/- 0.2, and 1.6 +/- 0.3 mg/dl) 24 h after ischemia. Furthermore, acute tubular necrosis scores were also similar in IL-1Ra-treated mice (3.0 +/- 0.3), IL-1R KO mice (2.7 +/- 0.3), and control mice (3.1 +/- 0.2). However, both IL-1Ra and IL-1R KO groups, compared with control animals, developed significantly less infiltration of polymorphonuclear leukocytes per 10 high-power fields in postischemic renal tissue (1111 +/- 228 and 967 +/- 198 versus 1820 +/- 190, P < 0.05). In contrast to the comparable renal functions at 24 h, recovery of renal function was significantly accelerated in the IL-1R KO group compared with control at both 48 (P < 0.05) and 72 (P < 0.05) h. Recovery in the IL-1Ra group was similar to that in the control animals. These data demonstrate that IL-1 is unlikely to be beneficial in the recovery of renal function after ischemia and may play a deleterious role.

Prevention of Salmonella typhimurium colonization of broilers with D-mannose

Broiler chickens can be contaminated by Salmonella typhimurium, which is a food safety concern. It has been previously shown that D-mannose blocks S. typhimurium adherence to chicken intestine in vitro. One-day-old broiler chickens were fed normal drinking water or drinking water supplemented with 2.5% mannose for 10 days. On Day 3, both groups were challenged orally with 1 x 10(8) S. typhimurium [ST-10 (Animal Diagnostics Laboratory, Ames, IA)] resistant to Nal and Nov (Sigma, St. Louis, MO). On Day 10 the birds' caecal contents were examined for the antibiotic-marked S. typhimurium. Two additional groups of birds were provided normal drinking water or mannose but were not challenged with the bacteria. Salmonella-challenged control chickens were 78, 82, and 93% colonized whereas Salmonella-challenged mannose-treated chickens were only 28, 21, and 43% colonized. Moreover, the mean log10 counts of control and mannose groups were significantly (P less than .001) reduced by at least 99%. Mannose-supplemented drinking water had no effect on weight gains. Certain carbohydrates may provide a means to reduce S. typhimurium contamination in broilers.

Minimally invasive radioguided parathyroidectomy in the reoperative neck

BACKGROUND

Operations for hyperparathyroidism (HPT) in a previously operated neck present a significant challenge and carry much higher morbidity rates than first-time operations. Our extensive experience with minimally invasive radioguided parathyroidectomy (MIRP) for first-time surgery for HPT has shown this method to be a directed approach to the offending adenoma, suggesting that the technique could be used to minimize reoperative neck surgery as well.

METHODS

Over an 11-month period 24 consecutive patients with primary HPT who had undergone at least one previous neck operation were referred for re-exploration. All patients underwent preoperative sestamibi scanning; 21 localized sufficiently to undergo MIRP.

RESULTS

All patients were cured after reoperation. Eighteen patients underwent MIRP under local anesthesia as outpatients; 3 MIRPs were done under general anesthesia. Average total operative time was 44 minutes, average incision length was 3.0 cm +/- 0.2 cm. Nineteen of the procedures were completed without any frozen sections. There were no complications.

CONCLUSION

MIRP is extremely effective in patients with HPT who have undergone previous neck exploration for parathyroid or thyroid disease. The technique allows for such a directed dissection that smaller incisions and local anesthesia in an outpatient setting are routine.

Epidermal growth factor accelerates functional recovery from ischaemic acute tubular necrosis in the rat: role of the epidermal growth factor receptor

1. Severe, ischaemic, acute tubular necrosis was induced in rats by bilateral occlusion of the renal arteries. The experimental group received exogenous epidermal growth factor infused directly into the renal arterial circulation. Serum creatinine concentration was measured daily for 1 week. Epidermal growth factor receptor binding was measured by autoradiography of whole kidney sections. Renal cell proliferation was measured by incorporation of [3H]thymidine into DNA. 2. Serum creatinine concentration increased after acute tubular necrosis with a peak at 48 h and remained elevated above control levels after 7 days. Binding of radiolabelled epidermal growth factor occurred in all regions of the kidney 48 h after ischaemia. Treatment with exogenous epidermal growth factor attenuated the rise in serum creatinine by 4 days after acute tubular necrosis and after 7 days serum creatinine was lower than in animals that did not receive epidermal growth factor. Infusion of epidermal growth factor also increased renal DNA synthesis. 3. The increase in epidermal growth factor binding in the kidney after acute tubular necrosis and the attenuation of the increase in serum creatinine concentration by administration of exogenous epidermal growth factor, suggest a role for epidermal growth factor in recovery from ischaemic damage. The increase in DNA synthesis in response to epidermal growth factor indicates that its effect may be due, at least in part, to accelerated tubular cell proliferation.

Plasmid DNA malaria vaccine: the potential for genomic integration after intramuscular injection

Plasmid-based (naked DNA) genetic vaccines are now entering clinical trials to test their safety and efficacy in healthy human volunteers. A safety concern unique to this new class of vaccines is the potential risk of deleterious integration into host cell genomic DNA following direct intramuscular injection. To address this issue experimentally, a preclinical safety study was conducted in mice to determine the structural nature of plasmid DNA sequences persisting in total muscle DNA at both 30 and 60 days following a single intramuscular injection of a plasmid expressing the Plasmodium falciparum circumsporozoite protein. In a protocol described for the first time, total DNA was extracted from muscle tissue and was subsequently linearized with a restriction endonuclease to enable agarose gel size fractionation of all extrachromosomal plasmid DNAs from high molecular weight mouse genomic DNA. Using PCR assays to quantitate plasmid-specific sequences, it was found that the amount of plasmid DNA persisting in muscle tissue varied but averaged about 10 fg per microgram of genomic DNA (in the range of 1500 copies per 150,000 genomes). In two of four separate experimental injections of mouse muscle, PCR assays of genomic DNA fractions indicated that agarose gel purification removed plasmid DNA down to a level of < or =3 copies per 150,000 mouse genomes. In the two other experimental samples, 3-30 copies of plasmid DNA remained associated with purified genomic DNA. The time following injection (i.e., 30 or 60 days) was not a factor in the number of copies of plasmid associating with genomic DNA and it was not possible to conclude if such sequences were covalently linked to genomic DNA or simply adventitiously associated with the genomic DNA. However, if an assumption is made that the highest level plasmid DNA found associated with genomic DNA (i.e., 30 copies) represented covalently integrated plasmid inserts and that each insert resulted in a mutational event, the calculated rate of mutation would be 3000 times less than the spontaneous mutation rate for mammalian genomes. This level of integration, if it should occur, was not considered to pose a significant safety concern.

If diabetes is a public health problem, why not treat it as one? A population-based approach to chronic illness

It is increasingly acknowledged that diabetes and other chronic illnesses are major public health problems. Medicare and many managed health care organizations have recognized the enormous personal and societal costs of uncontrolled diabetes in terms of complications, patient quality of life, and health care system resources. However, the current system of reactive acute-episode focused disease care practiced in many settings does not adequately address this public health problem. An alternative proactive, population-based approach to chronic illnesses such as diabetes is proposed and illustrated. This multilevel systems approach addresses supportive and inhibitory social-environmental factors at multiple levels (personal, family, health care team, work, neighborhood, community). Key disciplines contributing to a population-based approach to diabetes include epidemiology, behavioral science, health care services, public health, health economics, and quality of life professions. Current and potential contributions of each of these disciplines are illustrated and an integrative, population-based systems approach to diabetes management and prevention of complications is proposed. This approach is also seen as applicable to other chronic illnesses.

Inhibition by mannose of in vitro colonization of chicken small intestine by Salmonella typhimurium

The in vitro adherence of [3H]thymidine-labeled Salmonella typhimurium isolates to the small intestine of one-day-old chickens was investigated. Bacteria were screened for mannose sensitivity and mannose-resistance binding properties. Type 1 fimbriae positive strains adhered significantly better than Type 2 fimbriae-negative strains. Adherence was significantly (P less than .05) inhibited by D-mannose, methyl-alpha-D-mannoside, arabinose, and galactose. Adherence was both time and temperature dependent. These findings suggest that the small intestine of the chicken has receptors for bacteria with Type 1 fimbriae. The function of the receptors is dependent on a mannose moiety. Bacteria adhered better to fresh intestine cells than to cells held overnight at 4 C. Thus, adherence was dependent upon a metabolically active host cell. The in vitro adherence assay may further be used to study the interaction of bacteria with chicken enterocytes.

Activation of a low specific activity form of DNA polymerase alpha by inositol-1,4-bisphosphate

A low activity form of DNA polymerase alpha immunoaffinity-purified from adult-derived human fibroblasts was activated by interaction with phosphatidylinositol-4-monophosphate, while a high activity form of the enzyme did not interact with phosphatidylinositol-4-monophosphate or its derivatives. Phosphatidylinositol-4-monophosphate was apparently hydrolyzed in the presence of a highly purified low activity form of DNA polymerase alpha, effecting the release of diacylglycerol and the retention of inositol-1,4-bisphosphate by the enzyme complex. The resulting inositol-1,4-bisphosphate/protein complex exhibited increased affinity of binding to DNA template/primer and increased deoxynucleotidyltransferase activity. These data indicate that inositol-1,4-bisphosphate may function as an effector molecule in the activation of a low activity form of human DNA polymerase alpha and suggest that it may function as a second messenger during the initiation of mitosis in stimulated cells.